This invention relates to the production of a plastic container comprising an essentially planar base part and a detachable top part attached thereto, the top part comprising at least one compartment.
More particularly, the invention relates to a plastic container comprising a top part which is closed at its upper end and which has a sealable opening provided in the side wall of the top part, and a transparent base part, such that the base part after the removal of the top part from the base is suitable for use as a slide under a microscope.
Containers of the above-mentioned type find widespread use in the cultivation of cells and the subsequent investigation of the cell cultures formed.
Before a cell cultivation is started, a culture medium is introduced into the container through the opening in the side wall of the top part, and the culture medium is caused to form a uniform layer on the top surface of the planar base part. Subsequently, the cells are introduced into the container, which is then sealed and incubated for a certain period under suitable temperature conditions so as to form a cell layer on the base part.
The investigation of the cell layer thus formed is effected after removal of the top part from the base part and by placing the planar base part with the cell layer thereon under a microscope, the base acting as a slide.
Prior to the investigation of the cell layer under the microscope, the cell layer may be dyed or subjected to another pretreatment, if desired.
The plastic container should preferably be sealed during the cultivation in order to prevent undesired substances from entering into the container and culture medium, or to prevent cells or substances formed during the cultivation from leaving the container. In this connection it should be mentioned that the pressure within the container may raise somewhat during the cultivation phase.
On the other hand, the top part should be easily detachable from the base part when the cultivation is completed and the investigation is to be started.
Danish patent specification No. 133164 discloses a cultivation container of the above-mentioned type. This prior art container consists of a top part comprising several compartments, the top part being placed on the top surface of a planar base part, the zones located between the lower edges of the top part and the base part being sealed with a liquid-proof adhesive, such as a microcrystalline wax or an organopolysiloxane elastomer, which is introduced into these zones by injection through channels formed in the top part and opening into grooves provided on the lower edges.
The provision of these channels and grooves in the top part complicates the production of the prior art plastic container and furthermore, the prior art plastic container suffers from the defect that the injected adhesive tends to be non-uniformly distributed in the grooves, so that the container will not obtain the required tightness. Additionally, the prior art container tends to leak when the pressure within the container increases.
The object of the present invention is to provide a plastic container which is liquid-proof under normal culturing conditions and from which the top part can be easily removed after cultivation so as to allow the plane base to be used as a slide under a microscope.